Co-op Test Shaft

This unnamed Co-op Test Shaft featured in the cooperative campaign of Portal 2 is one of the nine Enrichment Shafts from the salt mines owned by Aperture Science Innovators, found underneath the computer-aided Enrichment Center.

This test shaft had originally ran through cooperative testing during the vintage era, but was later utilized by GLaDOS after she gains more sight of the facility with previous help of ATLAS and P-body. It is featured within Course 5: Mobility Gels.

Overview

 * After GLaDOS gains complete sight over the Enrichment Center, she discovers that there are hundreds if not thousands of human subjects kept in cryogenic stasis within a locked Extended Relaxation Annex, located just past this shaft. Unable to unlock the vault, she sends ATLAS and P-body to achieve her objective.


 * Like Test Shaft 09, this shaft was designed to test Mobility Gels but with two test subjects testing together, but only the Repulsion and Propulsion Gels. However according to GLaDOS this did not work, as humans "treat their friends as enemies", hence attempting to complete these tests with ATLAS and P-body.


 * Given the presence of the Propulsion Gel, the shaft was built sometime in the 70s and was later tempered and adjusted to the modern Aperture testing elements by GLaDOS.


 * The shaft is connected to the Hub through elevators, and to the Extended Relaxation Annex through a gargantuan hatch. As seen in Test Shaft 09, it is also connected to the other Enrichment Shafts through an underground train network.


 * While Chell had only ventured throughout Test Shaft 09, ATLAS and P-body were sent possibly further through the salt mines under orders from GLaDOS to recover stored human Test Subjects in the Extended Relaxation Annex.

Layout
The shaft is made out of 11 enrichment spheres.

(8 are test chambers, 3 are unknown)